The present invention relates to an arc blowing control method and apparatus used in a pulse arc welding process. More particularly, the invention relates to a method and an apparatus for controlling arc blowing in the pulse arc welding process, specifically, to suppress arc blowing in such a process.
Pulse arc welding is a process of binding and fixing a workpiece to a metal base by supplying an arc pulse current to an arc welding wire or rod, causing arc discharge to take place between the arc welding wire or rod and the base, and melting the arc welding wire or rod upon the base by means of heat generated during arcing. Pulse arc welding is easy in operation and produces superior bonding and, accordingly, is widely utilized in various manufacturing operations.
However, such pulse arc welding has a drawback in that, owing to fluctuations of the arc current and the like, a magnetic blowing of the arc may occur, thereby resulting in inferior welding.
More specifically, if the arc becomes weak due to a decrease in the arc current caused by fluctuation of the pulse arc current, the weakened arc can be bent by an attractive magnetic force towards the workpiece. The arc 100, as shown in FIGS. 1 to 3, changes from its normal state shown in FIG. 1 to an abnormal state shown in FIG. 2. This latter state results in the generation of what is termed arc blowing, specifically, magnetic arc blowing. As this magnetic blowing advances further, the arc 100 disappears, as shown in FIG. 3. At this time, molten material from the arc welding wire 200 may splatter. Further, the welding bead will be disturbed, thereby resulting in inferior welding.